Post-Doctoral Fellow Daiichi Sankyo, Inc. Manalapan, United States
Background: Peripheral T-cell lymphoma (PTCL) refers to a rare, heterogenous, and aggressive subset of non-Hodgkin lymphoma that develops from mature T-cells. PTCLs generally occur in patients who are 60 years and older but can manifest at any time. PTCLs are divided into three broad categories, leukemic, nodal, and extranodal. These lymphomas can be classified into specific subtypes with the most common being PTCL-not otherwise specified (PTCL-NOS), angioimmunoblastic T-cell lymphoma (AITL), anaplastic large cell lymphoma (ALCL), and cutaneous T-cell lymphoma (CTCL). In clinical practice, PTCLs are difficult to diagnose based on subtype due to their rarity and their intrinsic cytogenetic heterogeneity. Subtype-specific rarity makes it difficult to estimate their incidence and prevalence in the population. Prognosis for PTCL patients is poor, with a median 5-year overall survival of 30% among adults, though this varies by subtype (Petrich et al., 2015). Patterns of incidence and prevalence of PTCL in the United States (US) are not known.
Objectives: To estimate the overall, age-, sex-, and race-specific incidence and prevalence of PTCL in the US.
Methods: US Surveillance, Epidemiology, and End Results (SEER) 21 Registries, Nov. 2020 (2000-2018) were queried using SEER*Stat software (v8.4.0.1). SEER estimates were applied to the age-, gender- and race-specific 2020 US Census Bureau population data.
Results: The estimated annual incidence of PTCL in the US was 1.4 per 100,000 which corresponds to an estimated 4,654 new cases of PTCL diagnosed in the US every year. The incidence of PTCL increases with age, ranging from 0.0723 to 5.6061 per 100,000 in the 01-04 years and 80-84 years age groups, respectively. 80% of the cases are diagnosed after the age of 50 years. Age-specific annual incidence was consistently higher among males (47% higher than females) and black Americans (10% higher than Whites). There were an estimated 12,790 and 21,829 patients with PTCL who were diagnosed in the last 5- and 10-years, respectively, and were still alive (5- and 10-year prevalence). PTCL prevalence varies by sex, with 10-year prevalence in males (12,553) higher than females (9,320) (M:F=1.35). The estimated 10-year PTCL prevalence in Whites and Blacks was 17,335 and 2,971 respectively.
Conclusions: PTCL is a rare disease with an estimated 10-year US prevalence of 21,829. It is an aggressive cancer with most patients dying within 5 years of their diagnosis. These results highlight a significant unmet medical need for their treatment and improving their survival. Better reporting of subtype-specific diagnosis, based on cytogenetic testing, to cancer registries would improve the understanding of the epidemiology of subtype-specific PTCL.
